Re: [boost] typeof or similar

Subject: Re: [boost] typeof or similar
From: Mathias Gaunard (mathias.gaunard_at_[hidden])
Date: 2010-02-23 08:20:14

Steffen Roeber wrote:

> My preferred way would be something like a factory:
> 
> class Factory
> 
> {
> 
> public:
> 
>   template <class T>
> 
>   static Base *createDerived<T>()
> 
>   {
> 
>     return new DerivedT<T>();
> 
>   }
> 
> };
> 
>  
> 
> But how can I tell the factory which type to be used.
> 
> Base *derived = Factory::createDerived<sameAsBase> (base); //base is a Base
> *

You can't, since you lost that information.
Even if you stored a type identifier for T, you couldn't get the type 
out of it, all you can do is call a function depending on that type 
identifier.

> But Boost has some
> methods that by-pass some language constraints. I took a loot at something
> like 'typeof'.

typeof gives the static type of an object has deduced by the compiler, 
not the dynamic type.

So it's useless in your case.